Heated spray system for applying tanning solution

ABSTRACT

An improved method and apparatus for applying tanning solutions to a human body. Preferred embodiments of the present invention provide a spray gun that heats the air used to propel the tanning solution, rather than the tanning solution itself, in order to make the application of the tanning solution much more comfortable. Other preferred embodiments heat the tanning solution immediately before it is applied to minimize degradation of the active ingredient in the tanning solution that results from temperatures above 40° C.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a heated spray system, and more particularly to a heated spray system for applying tanning solution to a human body.

BACKGROUND OF THE INVENTION

“Tanned” skin is generally considered physically attractive. Tanning due to exposure to sunlight, however, causes undesirable skin damage, including sunburn, premature aging of the skin, and even increased risk of skin cancer. As a result, “sunless” tanning systems involving the application of a variety of topical skin tanning solutions have gained in popularity. These systems have the benefit of producing the appearance of tanned skin without exposure to potentially harmful ultraviolet light sources. Most systems involve the use of a compound containing the color additive dihydroxyacetone (DHA) to the skin, typically via a hand-applied lotion or cream or through spray nozzle systems.

Spray systems for dispensing tanning solution typically use air compressors and air-atomizing nozzles to form a fine mist of the tanning solution which can be sprayed onto the skin. Spray systems are faster and produce a more uniform coating that hand-applied lotions, however they do suffer from some disadvantages. Because the DHA-containing tanning solution is typically kept at room temperature, the spray application of a fine mist of the solution is often uncomfortably cold to the person being sprayed. Also, the solution takes several minutes to dry, and during the drying period tends to feel cold and sticky. The person being sprayed must essentially stand in place waiting for the solution to dry before getting dressed, which adds to the discomfort and also undesirably lengthens the total time required to receive a spray tan.

Accordingly, there is a need for an improved method and apparatus for applying tanning solutions to a human body that is both quicker and more comfortable.

SUMMARY OF THE INVENTION

An object of the invention is to provide an improved method and apparatus for applying tanning solutions to a human body. Preferred embodiments of the present invention provide a spray gun that heats the air used to propel the tanning solution, rather than the tanning solution itself, in order to make the application of the tanning solution much more comfortable. Other preferred embodiments heat the tanning solution immediately before it is applied to minimize degradation of the active ingredient in the tanning solution that results from temperatures above 40° C.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more thorough understanding of the present invention, and advantages thereof, reference is made to the drawings in the accompanying appendix.

FIG. 1 shows a spray gun according to a preferred embodiment of the present invention;

FIG. 2A shows another embodiment of a heating assembly that can be used in a preferred embodiment of the present invention;

FIG. 2B shows an exploded view of the heating assembly of FIG. 2A;

FIG. 3 shows an exploded view of a spray gun according to a preferred embodiment of the present invention using the heating assembly of FIG. 2A;

FIG. 4A shows the spray assembly of the spray gun of FIG. 3;

FIG. 4B shows an exploded view of the spray assembly of FIG. 4A;

FIG. 5A shows a side view of the fully assembled spray gun of FIG. 3;

FIG. 5B shows a front view of the fully assembled spray gun of FIG. 3;

FIG. 5C shows a top down view of the fully assembled spray gun of FIG. 3;

FIG. 6 shows another preferred embodiment of the present invention.

The drawings in the attached appendix are not drawn to scale unless otherwise indicated. In the drawings, reference numbers may be used with each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

For the purposes of the present invention, tanning solutions or sunless tanning solutions will be understood as meaning all substances or mixtures which are able to tan or darken the color of human skin. Most tanning solutions in use today contain 1,3-dihydroxyacetone (DHA) as an active ingredient. DHA, when applied topically to the skin, produces a skin browning effect that is similar in coloration to the tan produced by exposure to UV rays.

Typically, an airbrush-type spray gun is used for applying DHA-containing sunless tanning solutions. The most common type of spray gun used is known as a high volume low pressure (HVLP) spray gun, which uses a relatively high volume of air at a lower pressure than conventional high pressure air guns commonly used, for example, to apply paints or sealants. In a typical HVLP process, the air pressure at the nozzle is kept to less than 10 psi but the spray nozzle is designed to increase the volume of air directed at the fluid spray. HVLP systems usually make use of a turbine instead of an air compressor, but the present invention is not limited to turbine systems. Most spray guns used for tanning solution application are bleeder-type guns in which the compressed air is continually moving through the gun with only the DHA solution spray turned on and off with the trigger, although other types of suitable air gun systems could be used.

Because the DHA-containing tanning solution is typically kept at room temperature, the spray application of a fine mist of the solution is often uncomfortably cold to the person being sprayed. Also, the solution takes several minutes to dry, and during the drying period tends to feel cold and sticky. The person being sprayed must essentially stand in place waiting for the solution to dry before getting dressed, which adds to the discomfort and also undesirably lengthens the total time required to receive a spray tan.

Heating the solution itself would certainly improve the comfort level for anyone being sprayed with the tanning solution, but DHA is sensitive to high temperatures and begins to degrade at temperatures above 40° C. Applicant has determined that heating the solution itself to temperatures below 40° C. still results in a spray that it uncomfortably cold for most people. Applicant has also discovered, however, that it is not necessary to heat the solution itself above 40° C. as long as the air used to propel the atomized solution is heated to a comfortable level. For most users, the spray of atomized tanning solution will be comfortable if the blown air is heated to a temperature above 60° C. at the nozzle, more preferably above 80° C., and even more preferably above 95° C. (although temperatures may begin to be uncomfortably warm above 110° C.). Skilled persons will recognize that the air will be considerably cooler by the time it reaches the body of the person to whom the tanning solution is being applied.

FIG. 1 shows a spray gun according to a preferred embodiment of the present invention that heats the air used to propel the tanning solution in order to make the application of the tanning solution much more comfortable. In terms of the solution spraying process, the spray gun 100 of FIG. 1 operates in generally the same fashion as a prior art HVLC spray gun, although the present invention is not limited to HVLC spray guns and virtually any type of prior art spray gun could be used as long as the spray pressure is sufficiently low to use in applying solution to the human body.

Spray gun 100 makes use of a source of compressed or pressurized air such as turbine 103 and a reservoir of a tanning solution (in cup 104) to spray the solution through a spray tip 106. When trigger 108 is depressed the tanning solution mixes with the compressed air stream as described below and is released in a fine spray. Compressed air is forced through an air hose 110 connected to an air inlet 112 at the rear of the spray gun body 114. The gun body 114 also preferably includes a handle 116 for gripping and holding the gun during operation. The compressed air passes through an upper air channel 102 where it flows out spray tip 106, which includes an air cap 130 held in place by air cap ring 132.

The tanning solution is typically stored in a solution cup 104 as shown in FIG. 1, which is attached to the air gun by although gravity feed systems are also known. The tanning solution is moved up through a pick-up tube 118 and into a material flow passage 120 to an outlet 122 and needle valve 124. The needle valve 124, which is controlled by trigger 108, includes an elongated rod 125 and a tip 127 and is used to start and stop the flow of solution through the outlet 122. When the trigger 108 is pulled, the needle valve 124 is opened and the tanning solution from the material flow passage 120 is forced through the outlet 122 where it is atomized by the flow of compressed air and propelled toward a target. The material flow passage 120 can have a conically formed outer end (not shown) for receiving the tip of the needle valve or it can terminate in a threaded connection to a conically shaped nozzle 126.

In some known systems, the tanning solution is drawn up to the needle valve by siphon-feed. As compressed air flows past the needle valve orifice at the top of the pick-up tube, it creates a partial vacuum in the pick-up tube. An air return in the top of the solution cup allows atmospheric pressure to push the tanning solution up through the pick-up tube. In other known systems, such as the spray gun of FIG. 1, pressurized air can be forced through a discharge passage 128 and into the solution cup 104 to help push the tanning solution up through the pick-up tube 118. In either type of system, once the tanning solution is past the needle valve, the compressed air flowing through upper air channel 102 atomizes the solution and forces the atomized solution through air cap 130 which shapes the solution into a spray pattern.

Unlike prior art spray guns used for tanning solutions, the heated spray gun of FIG. 1 provides a heating assembly 140, which is housed within a heating manifold cover 141 that surrounds the upper air channel 102. Heating assembly 140 also includes heating element 142, which comprises heating coils 144, to raise the temperature of the air passing through the upper air channel so that the air exiting through the air cap has a temperature of approximately 60° C. to 95° C. Heating coils 144 are preferably controlled and adjusted via electrical connections 146 and a variable resistor or rheostat (not shown) so that the temperature of the air flowing from the spray gun has the desired temperature. The tanning solution itself is not heated. In some preferred embodiments, the pressurized air flowing through the discharge passage and into the solution cup has been warmed by the heating assembly, but does not heat the tanning solution to any significant degree. In other preferred embodiments, a siphon-feed can be used to provide a return of room temperature air. Also, pressurized air for the air discharge into the solution cup can be diverted before passing through the heating assembly so that the tanning solution is not indirectly heated.

In this manner, the compressed air passing out through the air nozzle is warm enough to be comfortable, but the tanning solution is not heated to a level where the DHA will be significantly degraded. Although the air is heated above room temperature to some degree by the compressor, the air cools rapidly as it moves through the air hose. For this reason, dedicated heaters located at or near the compressor unit are not effective in raising the air temperature to a comfortable level. In order to maintain the air at a desired comfortable temperature, it is desirable to heat the air as close to the air cap (outlet) as possible.

FIG. 2A shows another embodiment of a heating assembly 240 that can be used in a preferred embodiment of the present invention. FIG. 2B shows an exploded view of heating assembly 240. Referring also to FIG. 3 described below, heating assembly 240 is housed within the left and right halves of heating manifold cover 241. A heating element 242 is located within the air channel 201 through the heating assembly 240, and nested within a variety of shielding elements which serve to keep the heat contained within the heating assembly to prevent the outside of the spray gun from getting dangerously hot. These shielding elements will preferably include a phenolic shield 205 surrounding the heating element, which is further nested inside a paper heat shield 206 and a final heating element shield 207. Heating element shield is connected to the directional tube 209, which directs airflow up and through the heating assembly, by directional tube adaptor 208. Finally, thermal insulator 210 fits around nested elements 204 through 209.

Heating element 242 can comprise a typical coil resistance heater such as the one used in FIG. 1. Alternatively, other types of known heating elements could be used, including but not limited to other types of resistive heaters, ceramic disc heaters, solid element heaters, heaters using infrared or ultrasound waves, or thermal plasma heaters. In some preferred embodiments, where the heating element is capable of very rapid heating of the air supply, a bulky heating assembly such as the one shown in FIGS. 1 and 2 might not be necessary. Instead the heating element could be located much closer to the spray outlet and configured to heat the air just before it exits the spray gun outlet, such as within the material flow passage (shown by reference number 120 in FIG. 1). In other embodiments, the heating element used could be located anywhere along the air flow pathway as long as the combination of the temperature of the heated air and the cooling that takes place before the air reaches the person to which the tanning solution is applied results in an air temperature that is comfortable (preferably between 60° C. and 110° C. at the spray gun nozzle).

In some embodiments, a line heater, immersive heating element, or other suitable heating element could be used to actually heat up the tanning solution, either alone or in conjunction with heating the air as described herein. Although the DHA solution will begin to degrade at temperatures above 40° C., in some circumstances it would be possible to heat the solution immediately before application so that an unacceptable degree of degradation is avoided. Preferably, any DHA solution that is heated directly will be applied within 1 minute of heating; more preferably within 30 seconds of heating; and even more preferably within 1 second of heating. In some preferred embodiments this can be accomplished using a flow line heater located close to the spray discharge or by using an immersion heater to heat a small reservoir, preferably a secondary reservoir in addition to the primary sample cup, so that the heated solution can be sprayed within a suitable time after heating. For example, FIG. 6 shows a spray gun similar to the spray gun of FIG. 1, but without the heating assembly. Instead, line heater 602 is used to heat solution flowing through material flow passage 620 immediately before the nozzle. In embodiments using limited heating of the tanning solution, it would also be possible to use airless spray guns, which are known in the prior art.

FIG. 3 shows an exploded view of a spray gun 300 using the heating assembly of FIG. 2. FIG. 4A shows the spray assembly of spray gun 300 and FIG. 4B shows an exploded view of the spray assembly of FIG. 4A. FIGS. 5A to 5C show respectively side, front, and top down views of the fully assembled spray gun of FIG. 3. In the preferred embodiment shown in FIGS. 3 through 5C, the tanning solution is stored in cup 304. The tanning solution is moved up through a pick-up tube 318 and into a material flow passage 320 to an outlet 322 and needle valve 324. The needle valve 324, which is controlled by trigger 308, is used to start and stop the flow of solution through the outlet 322. In some preferred embodiments, the tanning solution is drawn up to the needle valve by siphon-feed. In other preferred embodiments, pressurized air is forced through a discharge passage 328 and into the solution cup 304 to help push the tanning solution up through the pick-up tube 318 into material flow passage 320. In either case, when the trigger 308 is pulled, the needle valve 324 is opened and the tanning solution from the material flow passage 320 is forced through the outlet 322 where it is atomized by the flow of compressed air and propelled toward a target. As in the embodiment of FIG. 1, the tanning solution itself is preferably not heated. Instead, the air that is used to propel the atomized tanning solution is heated to a temperature that makes the application of the tanning solution more comfortable.

A preferred method or apparatus of the present invention has many novel aspects, and because the invention can be embodied in different methods or apparatuses for different purposes, not every aspect need be present in every embodiment. Moreover, many of the aspects of the described embodiments may be separately patentable. The invention has broad applicability and can provide many benefits as described and shown in the examples above. The embodiments will vary greatly depending upon the specific application, and not every embodiment will provide all of the benefits and meet all of the objectives that are achievable by the invention.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made to the embodiments described herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. 

We claim as follows:
 1. A spraying apparatus for applying tanning solution to the human body comprising: a source of pressurized air; a reservoir of a tanning solution; a spray gun having a gun body and an air passage within the gun body to carry a flow of pressurized air for causing the tanning solution to flow from the reservoir through the nozzle for discharge in the form of a spray; a source of heat located within the gun body for heating the pressurized air flowing through the air passage without heating the tanning solution in the reservoir.
 2. The apparatus of claim 1, wherein the source of heat is a resistive heating element.
 3. The apparatus of claim 1, wherein the source of heat is a ceramic disc heater, a solid element heater, an infrared or ultrasound heater, or a thermal plasma heater.
 4. The apparatus of claim 1, wherein the spraying apparatus comprises an HVLC spray gun.
 5. The apparatus of claim 1, wherein the source of heat heats the pressurized air flowing through the air passage to a sufficient temperature that the air flowing out of the nozzle is from 60° C. to 110° C.
 6. The apparatus of claim 1, wherein the source of heat heats the pressurized air flowing through the air passage to a sufficient temperature that the air flowing out of the nozzle is from 80° C. to 110° C.
 7. The apparatus of claim 1, wherein the source of heat heats the pressurized air flowing through the air passage to a sufficient temperature that the air flowing out of the nozzle is from 95° C. to 110° C.
 8. The apparatus of claim 1, further comprising a heat shield surrounding the heating element.
 9. The apparatus of claim 1, wherein the source of heat is located within the air passage.
 10. The apparatus of claim 1, wherein the source of heat is located within the air passage and adjacent to the nozzle.
 11. A spraying apparatus for applying tanning solution to the human body comprising: a source of pressurized air; a reservoir of a tanning solution; a spray gun having a gun body and an air passage within the gun body to carry a flow of pressurized air for causing the tanning solution to flow from the reservoir through the nozzle for discharge in the form of a spray; a source of heat located heating a portion of the tanning solution to a temperature of greater than 40° C. so that the heated tanning solution can be discharged in the form of a spray within one minute of heating.
 12. The apparatus of claim 11 in which the heated tanning solution can be discharged in the form of a spray within 30 seconds of heating.
 13. The apparatus of claim 11 in which the heated tanning solution can be discharged in the form of a spray within 1 second of heating.
 14. The apparatus of claim 11 further comprising a source of heat located within the gun body for heating the pressurized air flowing through the air passage.
 15. The apparatus of claim 14 wherein the source of heat located within the gun body for heating the pressurized air heats the air flowing through the air passage to a sufficient temperature that the air flowing out of the nozzle is from 60° C. to 110° C.
 16. A method for applying tanning solution to the skin of a human body comprising: providing a reservoir of a tanning solution that, when applied topically to the skin, produces a skin browning effect; providing a spray gun for applying the tanning solution to the skin in the form of a spray by using a flow of pressurized air; heating the pressurized air so that the air flowing out of the spray gun is warmed to a temperature of 60° C. to 110° C.; and spraying the heated air and tanning solution onto a portion of the skin to produce a skin coloration similar to the tan produced by exposure to UV rays. 